Pump



Dec. 3, 1929. Y w. NELSON 1,738,309

l PUMP Filed Nov. 5, 192'? E@ i j@ e.

z 59 39 29,25 .f3/'ifa 55 l 1541152712 @maux ture of the Patented Dec. 3, 1929 PATENT OFFICE 'WILLIAM NELSON, OF MINNEAPOLIS, MINNESOTA PUMP Application filed November This invention relates to pumps of the valveless type, and aims to provide a neW and efficient pump capable of Wide utility.

A particular object of the invention is to 'Ll provide a positive displacement pump in which the displacement is provided by telescopically sliding members Which are moved 'at right angles to each other by an eccentric on the operating shaft. The slidingmem- 10 bers cause increase and decrease in the displacement chambers, and these chambers are in communication With ports in the operating shaft.

. Each of the displacement chambers is i 15 formed between the end of one of the sliding members and the Wall of the pump housing.

A further feature of the invention resides in the fact that the sliding members may be of cylindrical form to facilitate the manufacparts With close and accurate fitting.

These and other objects and advantages of the invention Will become apparent as the description proceeds. l

,While a preferred form of the invention has been disclosed for purposes of'illustration, it should be understood that various changes `may `bemade in the structure` and arrangement of parts jwithout departing 1 `30 from the spirit and scope of the invention as hereinafter set forth and claimed.

In the drawings: y lFig. 1 is a longitudinal section through a pump embodying the invention.

"Fig". 2 is a section on line 2-2 of Fig. 1.

Fig. 3 is a section on" line 3-3 of Fig. 1.

Fig. 4l is a diagrammatic perspective of the working parts of the pump. V

In carrying out the invention provision is .40 `made for a pump housing in which the secondary pump piston fits in such a manner that f it is free to slide in one direction, for example=vertically, but is restrained against all other movement. The primary piston fits Within the secondary in such manner that it can move only in a plane at right angles to the plane of motion of the secondary piston. The opposite ends of both primary and sec ondary pistons cooperate with thevvalls of the pump housing to form displacement 5, 1927. Serial No. 231,195.

chambers which may be utilized for pumping purposes. A shaft extends through the housing and through the primary and secondary pistons and carries an eccentric for operating the pistons. The pistons may be of prismatic or other suitable shape, although in the form illustrated the pistons are shown as being cylindrical, this form having certain advantages in manufacturing the parts With very small clearances.

Referring to the drawings more particularly, the reference numeral 10 indicates the pump housing, which is formed with a vertical cylindrical bore 11. The cylindrical`secondary piston 12 fits closely in the circum ference of bore 11, but is somewhat shorter than the vertical length of the bore, so that when the upper end of the bore is closed by the cover platel, a chamber 111 is formed below the piston 12 and a chamber 15 is formed above said piston;

A cylindrical horizontal bore 16 is formed through the secondary piston 12, and the primary piston `17 has a sliding fit in the `bore 16. The ends of piston 17 are curved to conform to the "shape of the bore 11, and thepiston 17 is shorter than the diameter of bore 11, leaving chambers 18 and 19 betweenthe opposite ends ofthe piston 17 and the casing 10. 2 i

rlhe operating shaft 2O has an eccentric 21 formed intermediate its length and carries at 1one end a reduced extension22 With an end 23 suitably formed to receive an operating device. A port 24Lformed in one side of the eccentric communicates With a bore 25 in the shaft,`ivhile a plurality of apertures 26 open through the periphery of the shaft into the bore 25. A port 27 formed in the eccentric on theiside opposite port 24 communicates with a bore 28 leading to the end of the shaft opposite the reduced extension 22. The pistous 12 and 17 are formed With bores 29 and 30 of a size to receive the eccentric 21 and entending at right angles to the bore 16. The casing 10 is also provided with a bore 31 receiving the-shaft,Y and With a reduced bore 32 .fitting about extension 22. A packing gland 33 prevents leakage at the driving end of the shaft. The casinglOis formed With an inlet chamber 34 surrounding the shaft at the apertures 26, and an inlet passage 35 conducts fiuid from the source of supply into the f inlet chamber. A discharge cover 36 fits over ports 41 and 42 leading from bore 30 to ports 39 and 40, respectively, and by ports 43 and 44 leading vfrom bore 30 to chambers 18 and 19 lrespectivelyl 'v rThe pump operates in the following manner: i f

Inthe position of Fig. 2 the cam is toward the'right.'v

f i As shaft rotates in a counter clockwise direction rthe primary piston 17 will be reciprocated laterally and the secondary piston 12 s will be reciprocated vertically by the travel v,of the eccentric 21. During the first phase of the movement from the position of Fig. 2 y.the `piston v17g-will start toward the left, and ,the piston 12 will move upwardly causing ,chambers- 14 and 19 to expand while the port A24 placesthese chambers in. communication `vvithfrthevinletport. At the same time the chambers 15 and 18 are contracted while they areopen to the outlet port 27. In this manner expanding chambersfarefdrawing fiuid in through? the inlet and contractingchambers are lforcing fiuid'out through the outlet continuously duringthe operation of the pump.

I claim: y 1.Ai .pump comprising a casing, a plurality of ftelescopically related cylindrical Y pistons mounted in Lthe casing and forming a pluralitygof jchambers, a shaft extending throughthe pistons and carrying an ecceny 1 tric for operating the pistons, the parts being formed vwith ports and passages providing in- Vlet andloutlet from the chambers.

2. Apumpfcomprising a casing, a cylindri- `cal secondary ,pistonA mounted for sliding in the 'casingv a cylindrical' primaryl piston mounted lfor sliding within the secondary piston, a shaft extending through the pistons and carrying an eccentric for operating the pistons, the parts being formed with ports and passagesproviding inlet and outlet from i kthe chambers. Y v

A. 3. Avpump comprising a housing, a cylindrical secondary piston fitting in the housing in such a manner as to leave chambers betweenopposite ends of the secondary piston and the housing, the secondary piston having acylindrical guideway formed therethrough, a cyhndrlcal primary piston fitting in the guideway m'such a mannerjas to leave chambers between opposite ends of the primary piston and the housing, the piston being formed with a shaftway extending at right angles to the guideway, and a shaft extending through the shaftway and carrying an eccentric within the primary piston.

4. A pump comprising a housing, a cylindrical secondary piston fittingV in the housing in such a manner as to leave the chambers between opposite ends of the secondary piston and the housing, the secondary piston having a cylindrical guideway formed therethrough, a cylindrical primary piston fitting in the guideway in such a manner as to leave chambers between opposite ends of the primary piston and the housing, the piston being formed with a shaftway extending at right angles to the guideway, and a. shaft extending through the shaftway and carrying an eccentric within the primary piston, the parts being formed with ports and passages providing inlet and outlet from the chambers.

5. A pump comprising a housing, a cylindrical secondary piston fitting in the housing in such a manner as to leave secondary chambers between opposite ends of the piston and the housing, the secondary piston being formed with a cylindrical guideway and with ports leading from the guideway to the secondary chambers, a cylindrical primary piston fitting in the guideway in such a manner as to leave primary chambers between opposite ends of the primary piston and the housing, the pistons being formed with a shaftway, and the primary piston having ports leading from the shaftway to the primary chambers, and with other ports leading from the shaftway to the ports in the secondary piston, a shaft extending through the shaftway and carrying an eccentric within the primary piston, the shaft being formed with inlet and discharge passages leading to ports on the circumference of the eccentric.

6. A pump comprising a housing, a secondary piston' fitting in the housing in such a manner as to leave chambers between oppo- Y site ends of the secondary piston and the housing, the secondary plston having a guideway formed therethrough, a primary piston fitting in the guideway in such a' manner as to leave chambers between opposite ends of the primary piston and the housing, the piston being formed with a shaftway extending at right angles to the guideway, and a shaft extending through the shaftway and carrying an eccentric. within the primary piston.

7. A pump comprising a housing, a secondary piston fitting in the housing in such a manner asto leave chambers between opposite ends of the secondary piston and the housing, the secondary piston having a guideway formed therethrough, a primary piston fitting in the guideway in such a manner as to leave chambers between opposite ends of the primary piston and the housing, the piston being formed With a shaftway extending at right angles to the guideway, a shaft extending through the shaftvvay and carrying an eccentric Within the primary piston, the parts being formed with ports and passages providing inlet and outlet from the chambers.

8. A pump comprising a housing, a secondary piston iitting in the housing in such a manner as to leave secondary chambers between Opposite ends of the piston and the housing, the secondary piston being formed with a cylindrical guideway and with ports leading from the guideway to the secondary chambers, a primary piston fitting in the guideway insuch a manner as to leave primary chambers between opposite ends of the primary piston and the housing, the pistons being formed with a shaftvvay, and the primary piston having ports leading from the shaftway to the primary chambers and with other ports leading from the shaftvvay to the ports in the secondary piston7 a shaft extending through the shaftway and carrying an eccentric Within the primary piston, the shaft being formed with inlet and discharge passages leading to ports on the circumference of the eccentric.

In testimony whereof I aHiX my signature.

WILLIAM NELSON. 

